ANALYTICAL METHOD FOR DETERMINING DIRECT CURRENT POWER SYSTEM STABILITY.

A practical method is presented for analytically determining the stability margins for an EMI filter tied to the input of a constant power switching regulator. The constant power regulator presents a potential stability problem because of its negative impedance characteristic at the power input terminals. The method is also extended to determine stability of an entire power system bus. With this method, power system stability can be predicted before system tests are started thus possibly preventing costly design modifications. Another key is that the computational part of the analysis may be performed with a linear ac circuit analysis computer program such as ECAP. Being able to use such programs rather than transient simulation programs will save time and money.